Oleoresins, lipids and other terpenoids are natural products of growing pine trees. The majority of these compounds are synthesized within the living tree by special cells called epithelial cells which line the vertical and horizontal resin ducts. The resin produced by the epithelial cells is then secreted into the lumen of the resin ducts.
The oleoresins and tall oil derivatives find numerous applications in the manufacture of protective coatings, emulsifiers, soaps, detergents, food stuffs, plasticizers, dimer acids, lubricants, textile chemicals and others.
Heretofore, it has been shown that bipyridylium compounds can induce increased production of oleoresin material in living, standing pine trees. See, Roberts, U.S. Pat. No. 3,839,823. The living tree is typically treated with a chemical solution by applying the solution to a treatment site on the living tree. Treatment sites have been prepared by various methods, such as: removing a small section of bark to expose sapwood, making an axe cut deep enough to expose sapwood, or by boring a small downwardly sloping hole into the sapwood. See, Brown, U.S. Pat. No. 2,971,159. The purpose of these treatment sites is to permit the chemical solution to be adsorbed into the living cells of the tree. Once applied to a living tree, the chemical is mobile and may be carried to distant areas within the tree. The chemical, once absorbed into the living cells of the bark, and wood (xylem) induces the cells to produce and secret copious amounts of oleoresin into other adjacent wood fibers until the wood becomes resin or "pitch" soaked. At least some of the carbon necessary to carry out the synthesis of the oleoresins comes from sugars and other substrates ultimately produced by photosynthesis in the leaves of the living tree. In this manner, the oleoresin production of a living tree may, after a period of from six to twelve months following treatment, be increased many fold. Following the treatment period, the tree must be felled and the heavy "pitch" soaked portions are then transported to an extraction plant where the oleoresins and tall oil components are extracted from the wood using methods well known in the art.
The foregoing methods, however, have a number of disadvantages. Trees treated by previously known methods often leave the treated trees subject to attack by bark beetles, such as the Ips species, which often results in high tree mortality. This makes the practical application of the previously known methods of treatment a high risk to current forest management practices, especially throughout the Southeast.
Due to the highly toxic nature of bipyridylium salts, their wide spread use in a living forest presents dangers to humans and animals alike. Currently, the use of bipyridylium salts has not been approved by the Environmental Protection Agency for use in forests to induce oleoresin production.
Additionally, large amounts of time are usually required to treat the living trees in the forest, cut the trees, saw the trees into useable sections and transport the wood from the forest to a processing site. Therefore, the amount of labor required by some of these prior methods may make them economically unattractive.
The present invention permits the treatment of living portions of pine trees with dilute solutions of a bipyridylium salt to increase the amount of extractable oleoresinous and tall oil materials at sites where exact and precise control can be exercised over the toxic chemicals necessary to the practice of the present invention. The present invention also permits the amount of extractable oleoresinous and tall oil material to be increased during periods of storage which had heretofore resulted in reduced amounts of such materials being available for extraction. Furthermore, the present invention provides a method for increasing the extractable oleoreinous and tall oil material from woody material, such as needles twigs, and roots which had heretofore been thought of as only waste material.
It has been found that the present method permits synthesis of oleoresin and tall oil materials in the absence of current photosynthesis by utilizing the stored foods, starch, lipids and amino acids already present in the tree.
Accordingly, it is an object of the present invention to provide an improved method of chemically increasing oleoresin and tall oil production in living pine wood or other portions of the pine tree.
Another object of the present invention is to provide a method of chemically increasing the amount of extractable oleoresinous and tall oil material from living portions of pine trees.
Yet another object of the present invention is to provide a method of chemically increasing the amount of extractable oleoresinous and tall oil material from living portions of pine trees at a site removed from the forest where exact and precise control can be exercised over the toxic chemicals used in the present invention.
A further object of the present invention is to provide a method of chemically increasing the amount of extractable oleoresinous and tall oil material from living portions of pine trees such that the period of time between treatment and realization of the increased extractable oleoresin and tall oil is greatly reduced.
Another object of the present invention is to provide a method of chemically increasing the amount of extractable oleoresinous and tall oil material from living portions of pine trees which have not heretofore been useable for oleoresin and tall oil production.
These and other objects, features and advantages of the present invention will become apparent from a review of the following detailed description of the disclosed embodiment and the appended claims.